Stan Wood, DVM, Diplomate ABVP

Specialist in Canine & Feline Practice

Staph Dermatitis and Hypersensitivity

Staph is a commonly used abbreviation for Staphylococcus, a group of bacteria commonly found on the skin. Dermatitis is a term that means that the skin is inflamed.

Staph is a normal resident of the skin of animals and humans; however, it is considered an opportunist. As long as the skin is healthy, Staph is dormant. But once the skin is irritated, Staph can invade the area and multiply rapidly.

Causes of Skin Irritation

Scratching is the most common cause. Any disorder that causes itching can create the situation that allows Staph to become a problem. Common causes of itching include fleas, inhalant allergy, and food allergy. Irritating chemicals, such as flea and tick dips, also can cause itching.

Diagnosis of Staph Lesions

There are two typical Staph lesions. One type begins as a red area on the skin with a pimple-like pustule in the center. The other type is a circular, reddish area with a crusty edge and hair loss in the center. The latter can easily be confused with ringworm. Finding either of these skin patterns in a dog that is scratching is highly suggestive of Staph.

Confirmation can be made with cultures or skin biopsy. However, the lesions are so typical that this is usually not necessary.

Treatment of Staph Dermatitis

This bacterium is usually sensitive to several antibiotics. These include erythromycin, enrofloxacin, amoxicillin with clavulanic acid, lincomycin, dicloxacillin, and oxacillin. Since these medications can be given orally, treatment can occur at home. However, some infections may require 3-6 weeks of treatment before the infection is under control. Antibacterial shampoos and ointments can also be helpful in bring about rapid control of the infection.

The other essential part of treatment is stopping itching and scratching. Other tests may be needed to determine the cause or causes. Frequently, more than one condition contributes to itching.

Contagion

Your dog is not contagious to you or to other pets. All dogs, cats, and people have Staph living on the skin as a normal resident.

Rapid Recurrence following Treatment

If the Staph lesions return within a week or two following treatment, another situation may exist. This situation may be caused by an allergy to the Staph bacteria. This is called Staph hypersensitivity or Staph allergy.

The skin lesions that are caused by this disease are identical to those of a Staph dermatitis. The difference is recurrence. If Staph dermatitis is treated properly, the underlying cause is eliminated and itching is stopped, the bacterial skin disease should be eliminated. This situation may return if itching returns. However, when the dog with Staph hypersensitivity is treated, the skin lesions will return within a few days or weeks.

Since differentiation of Staph dermatitis and Staph hypersensitivity is based largely on recurrence, it is very important that treatment be continued long enough. This often means a month or more of antibiotics. If not, there will still be a question of which disease is present.

Treatment of Staph Hypersensitivity

Treatment begins the same as for Staph dermatitis: oral antibiotics, medicated shampooing, and whatever is necessary to stop the itching. However, long-term control is best achieved with Staph bacterin. Staph bacterin is a solution of killed Staph bacteria that is injected into the dog in very tiny amounts. This is an attempt to reprogram the dog's immune system so it does not over-react to its own bacteria. The use of Staph bacterin begins as a series of daily injections into the layers of the skin. After the initial series is completed, the injections are given subcutaneously (just below the skin) on an interval of every 3-4 days to every 2 weeks. Since this is an ongoing treatment, it is done by you at home.

Fear of Injections

Giving injections to dogs is much easier than you think. We can teach most people to give the injections in just a few minutes. Don't decide that you cannot do this until we show you the technique. However, if after seeing the technique you are still not comfortable doing it, we can arrange for one of our staff members to do these for you on a regular basis.

Success Rate

Allergy shots are never successful 100% of the time, whether in dogs or in people. We expect up to 75% of the dogs to respond well.

Other Options Besides Injections

If you do not give the injections, you cannot arrange for one of our staff members to do so, or your dog does not respond, it will have to be treated periodically with oral antibiotics and medicated baths. This is not the most desirable approach because Staph will often develop resistance to the antibiotics. If this occurs, a change in the specific antibiotic used will be necessary.

INSTRUCTIONS

____1. Give the antibiotics orally according to the instructions on the label. Do not discontinue them even though your dog's skin looks normal. There should be noticeable improvement within 1 week. If not, please contact us. If the skin lesions are improved but not completely healed when the antibiotics are all given, contact us for either a refill or for another drug.

____2. Bathe your dog in the medicated shampoo every _________ days for a total of _______ baths. Work up a lather and allow it to remain on your dog's skin for at least 5 minutes before rinsing thoroughly.

____3. An injection was given to stop itching. If this does not occur within 24 hours, please contact us for further instructions. If the injection causes your dog to drink and urinate excessively, pleases contact us. If this occurs, it will stop in a few days. It is dose related; if another injection is needed at a later date, the dose will be lowered to avoid this problem.

____4. A prescription is dispensed to control itching. Give the first dose ___________________. If the tablets cause your dog to drink or urinate excessively, please contact us. If this occurs, it will stop in a few days. It is dose related; if this medication is resumed, the dose will be lowered to avoid this problem.

____5. Staph bacterin is to be given according to the following schedule:

Dose 1: ______________________ Dose 5: ____________________

Dose 2: ______________________ Dose 6: _____________________

Dose 3: ______________________ Dose 7: _____________________

Dose 4: ______________________ Dose 8: _____________________

Please make an appointment on each of these days.

Following this series you will be instructed on how to give the injections at home.